The name of the software to be made available. If the name is common, inconsistent, or otherwise ambiguous it should be combined with one or more identifiers in the specs field.
One or more IRIs identifying resources for installing or enabling the software named in the package field. Implementations may provide resolvers which map these software identifier IRIs to some configuration action; or they can use only the name from the package field on a best effort basis.
The (optional) versions of the software that are known to be compatible.